1. Field of the Invention
The present invention is related to the LED driving circuits, and in particular, related to the LED driving circuits that suppress brightness error.
2. Description of the Related Art
In a LED display, brightness errors often occur among different modules because of the driving current variations thereof. For a full-color display, when the driving current is inaccurate, the screen is prone to color blocks, and the display quality is negatively affected.
Brightness errors usually occur due to inter-channel current errors or inter-chip current errors. The inter-chip current errors are caused due to process drift between different ICs which are manufactured in different batches. Though it is difficult to prevent process drifts, there are various manners in the prior art to deal with the inter-chip current errors. The contemporary approaches have limited effect on obliterating the inter-chip current errors.
In general, the human eyes can discern the brightness difference of 6% difference or above, the human eyes can even discern the brightness difference of 1% for low-brightness image frames. Thus, merely obviating the inter-chip current errors is insufficient to meet the requirements of today's high-definition displays. In view of this deficiency, the present invention provides new LED drivers that suppress brightness errors of the LED display by reducing the inter-channel current errors.